19725929805 has 16 divisors (see below), whose sum is σ = 31762520064. Its totient is φ = 10453485120.

The previous prime is 19725929777. The next prime is 19725929807. The reversal of 19725929805 is 50892952791.

It is not a de Polignac number, because 19725929805 - 2²⁰ = 19724881229 is a prime.

It is a super-2 number, since 2×19725929805² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19725929807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4185741 + ... + 4190450.

It is an arithmetic number, because the mean of its divisors is an integer number (1985157504).

Almost surely, 2^19725929805 is an apocalyptic number.

19725929805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19725929805 is a deficient number, since it is larger than the sum of its proper divisors (12036590259).

19725929805 is a wasteful number, since it uses less digits than its factorization.

19725929805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8376356.

The product of its (nonzero) digits is 4082400, while the sum is 57.

The spelling of 19725929805 in words is "nineteen billion, seven hundred twenty-five million, nine hundred twenty-nine thousand, eight hundred five".